PlayerAdded load hat?

Let's start by tabbing your code correctly:

game.Players.PlayerAdded:connect(function(player)
	player.CharacterAdded:connect(function(character)   
		save = player.HatSave.Value

		for i, v in pairs(player:GetChildren()) do
			if v.ClassName == "Hat" and v.Name == save then
				v.Parent = player.Character
			end
		end 

		wait(2)

		for i, v in pairs(character:GetChildren()) do
			if v.ClassName == "Hat" and v.Name ~= save then
				v:Destroy()
			end
		end
-- If you had tabbed correctly, you would have realized you are missing an `end)` here!
end)